The present invention relates to a welding device and more particularly pertains to a synchronous ultrasonic metal welding device with double-heads.
Present ultrasonic metal welding devices mainly have a structure wherein one ultrasonic energy converter is installed at one welding device. Occasionally, double ultrasonic energy converter structure could be found wherein two ultrasonic energy converters are installed at one welding device to operate synchronously on the same single mold on the same single plane so as to strengthen the weld on the same workpiece. This imposes restrictions on the manufacturing process for present metal pieces of power batteries. With the gradual shortage of energy and the increasingly adverse effects on the human living environment caused by the discharge of waste gas, waste water and solid waste to the biological environment, the tension has already been heightened. To cater for the needs of the market, high-power recyclable power batteries with zero waste discharge and zero secondary pollution (e.g. lithium batteries) are promoted, and eventually motor vehicles and ships and so forth which are powered by power batteries will also be more popularized. Such high-power batteries are advantageous in that they have high battery capacity and load as well as high amplitude and efficiency, but their terminal structure must be multi-layer (tens or hundreds of multi-layer copper, multi-layer tin, multi-layer nickel or multi-layer aluminum, etc). The multi-layer metal pieces are welded on a terminal tab with one half on a first side and the other half on a second side parallel and opposite to the first side. If welding is done by traditional welding device with only one ultrasonic energy converter installed at one welding device, it is necessary to first weld the first side, and then turn-around and weld the second side, and the following manufacturing problems arise with such operation procedure: First, using the first welding position as the bottom die pad would not fulfill the smooth grade requirement, which results in poor effect for the second welding, and the welded layers are uneven. Second, when welding for the second time, the multi-layer metal pieces which have been welded at the first welding will be loosened by vibration or even detached by impact, thereby resulting in operation failure and thus becoming rejected products due to failure to meet standards.